text: import pytest
  from safeqthreads import errors, descriptors
  
  
  def test_stop_running_descriptor():
      ''' check to see that the can set and get from 
          this descriptor correctly
      '''
      class Tester(object):
          stop_running = descriptors.StopRunning()
  
      tester = Tester()
      # test that stop_running is False by default
      assert tester.stop_running is False
      
      # test that it must be a boolean
      with pytest.raises(errors.StopRunningNotBoolError):
          tester.stop_running = 22
      
      # and that we can change its value
      tester.stop_running = True
      assert tester.stop_running is True
      tester.stop_running = False
      assert tester.stop_running is False
  